As scientist probe nature ever more precisely with laser pulses, now aiming for the zeptosecond regime – a trillionth of a billionth of a second and the fastest scale of time measured – optimizing each parameter of those pulses can offer more finely tuned measurements of as-yet unknown dynamic properties. The laser wavelength, duration and energy of each pulse, and rate at which pulses are produced are all key factors in observing dynamics such as the real-time electron motions of single molecules together with the motion of consistituent atoms.